Persons with diseases such as diabetic neuropathy, arteriosclerosis, spinal stenosis, and the like often experience difficulty or inability in ambulation (walking). At the same time, if such patients do not force themselves to walk--despite such difficulty or pain--their condition may worsen over time, to the point where the inability to walk becomes irreversible.
Canes, crutches and multi-legged walkers are often prescribed, but many patients find these difficult and cumbersome to use. Often, the only comfortable alternative is a wheelchair, which itself can be the cause of progressive ambulatory deterioration.
Prior developments in this field may be generally illustrated by reference to the following patents:
______________________________________ Patent No. Patentee Issue Date ______________________________________ 4,941,670 D. Parr Jul. 17, 1990 2,530,544 O. Schwantes Nov. 21, 1950 4,681,332 D. Malone Jul. 21, 1987 1,658,068 A. White Feb. 07, 1928 1,482,506 T. Bradford Feb. 05, 1924 4,775,162 J. Chao Oct. 04, 1988 4,552,372 D. Jones Nov. 12, 1985 3,333,862 J. Rockwell Aug. 01, 1967 ______________________________________
U.S. Pat. No. 4,941,670 teaches a mobile push-type toy vehicle having skateboard wheels. It cannot be steered, other than by leaning.
U.S. Pat. No. 4,681,332 teaches a collapsible four-wheeled vehicle which also has no rotatable steering means. The vehicle may be used to train skaters.
U.S. Pat. No. 2,530,544 teaches a walking chair with four wheels. It is steered by swivel casters, which can be a cumbersome and tiring steering method. The construction of the seat is such that the operator would have to be either freely standing or fully seated in order to use the device, such that in the latter case his or her feet would not be able to complete a normal stride. That is to say, in this prior art device, the patient's knees must always remain in front of the edge of the chair seat when the patient is seated. It is therefore unsuited for therapy which attempts to replicate a patient's normal stride.
The rest of the patents are representative of what is in the art.